evaluation of serum vitamin d levels in patients with vitiligo undergoing nbuvb (narrowband uv-b) therapy

background: vitamin d increases the contents of tyrosinase in cultured human melanocytes, which raises its possible role in modulating melanogenesis. objectives: in this study, the level of 25 (oh) d was measured before and after nbuvb therapy and its relationship with outcome of nbuvb therapy in patients with vitiligo was also assessed. methods: this study was conducted on 30 patients with generalized vitiligo (less than 30% body surface) and 30 healthy individuals without age and gender limitations. the patients received nbuvb therapy 2 times a week for 15 weeks. we measured the serum vitamin d level and involvement area (vasi score, vitiligo area, and severity index) at baseline and 30 sessions post treatment. results: the level of vitamin d increased significantly compared to baseline measurements. vitamin d level changes were not significantly associated with clinical outcome in which vasi score decreased. conclusions: vitamin d did not improve clinical outcomes. thus, we suggest that further studies be conducted to understand the mechanisms of pigmentation due to nbuvb therapy in vitiligo.